JP2009180885A - Developer stirring unit, developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer stirring unit, a developing device and an image forming apparatus that correctly determine a remainder amount of developer in accommodating tank. <P>SOLUTION: The developer stirring unit comprises: an accommodating tank that accommodates developer; a stirring member that has at least one shaft portion and is used to stir the developer accommodated in the accommodating tank; a bearing member that couples with the shaft portion, and supports the stirring member to possibly rotate around the shaft portion serving as rotation axis and to possibly move along an axis direction of the rotation axis; a driving section that drives the stirring member to rotate; and a determining section that determines a remainder amount of the developer in the accommodating tank. In the developer stirring unit, a bearing inclination part, which inclines in the axial direction, is formed in the part where the bearing member is in contact with the stirring member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a developer agitating device for agitating a developer, a developing device including the developer agitating device, and an image forming apparatus, and more particularly to a developer agitating device capable of detecting the remaining amount of developer, and development. The present invention relates to an apparatus and an image forming apparatus.

  In recent years, electrophotographic image forming apparatuses are widely used in printers, facsimiles, copiers, multifunction machines, and the like. Here, the electrophotographic system generally refers to an image forming system comprising processes of charging, exposure, development, transfer, fixing, and cleaning. Among these processes, in the development process, a developer consisting of toner is carried on a photosensitive drum as an electrostatic latent image carrier by a developing roller as a developer carrier to develop an electrostatic latent image. A developing device that performs is used.

  In general, such a developing device is provided with a supply roller for supplying toner to the developing roller and a toner stirring device as a developer stirring device for stirring the toner in addition to the developing roller described above. It is done.

FIG. 16 is an explanatory view showing a conventional toner stirring device.
As shown in FIG. 16A, the toner stirring device 100 includes a toner hopper 102 as a storage tank for storing the toner 101, a stirring bar 103 as a stirring member, and a drive unit 104. The stirring bar 103 includes a magnet 105 and is rotatably supported in the toner hopper 102 by a support shaft 106. A protrusion 106 a is formed at the end of the support shaft 106, and the drive unit 104 presses the protrusion 106 a to rotate the support shaft 106 and the stirring bar 103 in the direction indicated by the arrow A. A magnetic sensor 107 capable of detecting the strength of the magnetic field from the magnet 105 is disposed below the bottom surface of the toner hopper 102.

When a rotational force from a driving device (not shown) is transmitted and the driving unit 104 rotates, the stirring bar 103 rotates together with the support shaft 106, and after the tip rotates to the uppermost position, that is, the top dead center position, It rotates faster than the drive unit 104 and falls. Then, as shown in FIG. 16A, the stirring bar 103 stops on the toner 101 accommodated in the toner hopper 102. At this time, a control circuit (not shown) determines the stop position of the stirring bar 103, that is, the remaining amount of toner 101 in the toner hopper 102 based on the strength of the magnetic field detected by the magnetic sensor 107.
Japanese Patent Laid-Open No. 9-54488

  However, in the conventional toner agitation apparatus 100 described above, when the remaining amount of the toner 101 in the toner hopper 102 decreases, as shown in FIG. 16B, the agitation bar 103 that has fallen rebounds or vibrates. As a result, there is a problem that the remaining amount of toner cannot be accurately determined.

  Therefore, a developer stirring device, a developing device, and an image forming apparatus that can accurately determine the remaining amount of developer in the storage tank have been desired.

  The present invention adopts the following configuration in order to solve the above points.

<Configuration 1>
A developer stirring device according to the present invention includes a storage tank for storing a developer, a stirring member for stirring the developer stored in the storage tank, and at least one shaft portion. A bearing member that supports the agitation member to be rotatable about the rotation axis and movable in the axial direction of the rotation axis, and a drive unit that rotationally drives the agitation member; And a determination unit for determining the remaining amount of developer in the tank, wherein the agitating member is rotated along the rotation direction of the rotation shaft and is moved along the axial direction of the rotation shaft. .

<Configuration 2>
The developing device according to the present invention includes the developer stirring device described above.

<Configuration 3>
An image forming apparatus according to the present invention includes the above-described developing device.

  According to the developer agitating device, the developing device, and the image forming apparatus of the present invention, the agitating member falls along the bearing member while moving in the rotation axis direction. Bounce and vibration are prevented. Accordingly, the remaining amount of developer can be accurately determined.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a case where the present invention is applied to a toner stirrer and an electrophotographic printer including a developing device having the toner stirrer will be described as an example.

FIG. 2 is a schematic side view showing the configuration of the printer according to the present invention.
As shown in FIG. 2, the printer 10 is an electrophotographic image forming apparatus having a toner stirring device and a developing device, and as shown in FIG. 2, a paper feed mechanism unit 11, a printing mechanism unit 12, a fixing mechanism unit 13, and a paper discharge mechanism. The mechanism part 14 is provided.

  In addition, the printer 10 includes a printer control unit (not shown) for controlling each unit. The printer control unit includes a control board 15 and supplies a voltage from a power supply unit (not shown) to each unit, drives each motor (not shown) for rotating each roller described later, print control based on information from each sensor, etc. I do. The printer control unit functions as a determination unit that determines the remaining amount of toner as a developer.

  As the printing process starts, the printer control unit starts energizing the fixing mechanism unit 13.

  As shown in FIG. 2, the fixing mechanism unit 13 includes a heat roller 16 having a heat source therein and a backup roller 17.

  When the surface of the heat roller 16 reaches a predetermined fixing temperature, the printer control unit starts rotation of each roller in the printing mechanism unit 12. Then, paper feeding to the printing mechanism unit 12 by the paper feeding mechanism unit 11 is started at a predetermined timing.

  As shown in FIG. 2, the paper feed mechanism unit 11 is provided at the lower portion of the printer 10, and includes a cassette 19 that accommodates a plurality of print media 18, a hopping roller 20, an upper registration roller 21, and a lower registration roller. 22.

  When the hopping roller 20 starts rotating under the control of the printer controller, the print medium 18 accommodated in the cassette 19 is conveyed to the medium conveyance path. The printing medium 18 is conveyed to the printing mechanism unit 12 by the rotation of the upper registration roller 21 and the lower registration roller 22.

FIG. 3 is a schematic side view showing the configuration of the printing mechanism section.
As shown in FIGS. 2 and 3, the printing mechanism unit 12 includes an image forming unit 23 including a developing device, an exposure device 24, and a transfer roller 25.

  The image forming unit 23 includes a photosensitive drum 26 as an image carrier. The photosensitive drum 26 is exposed at the lower part of the image forming unit 23, and the surface thereof is disposed in contact with the transfer roller 25.

  Inside the image forming unit 23, around the photosensitive drum 26, there are a charging roller 27 as a charger, a developing roller 28 as a developer carrier, and a cleaning roller 29 as a cleaning unit, respectively. 26 is disposed in contact with the surface of 26.

  Further, inside the image forming unit 23, a sponge roller 30 as a developer supply member and a blade 31 as a layer regulating member are arranged around the developing roller 28.

  Further, a toner cartridge 32 for accommodating toner as a developer is detachably mounted on the upper portion of the image forming unit 23. The toner cartridge 32 has a toner storage space 33 for storing toner therein and a shutter (not shown). When a lever (not shown) is rotated after the toner cartridge 32 is mounted at a predetermined position, the shutter of the toner cartridge 32 is opened, and the toner stored in the toner storage space 33 is stored in the toner holding space inside the image forming unit 23. 34 is replenished and held. The toner held in the toner holding space 34 is supplied to the developing roller 28 by the sponge roller 30, and a toner layer having a predetermined thickness is formed on the surface of the developing roller 28 by the blade 31.

  Further, a sensor unit 35 for detecting the remaining amount of toner in the toner holding space 34 is disposed inside the image forming unit 23. Details of the sensor unit 35 will be described later.

  When the print medium 18 fed by the paper feed mechanism unit 11 reaches a predetermined position, the printer control unit uniformly charges the surface of the photosensitive drum 26 by the charging roller 27 and then causes the exposure device 24 to emit light. . As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 26. The toner on the developing roller 28 adheres to the electrostatic latent image, and a toner image is formed on the surface of the photosensitive drum 26.

  When the print medium 18 is further conveyed and reaches between the photosensitive drum 26 and the transfer roller 25, the toner image on the photosensitive drum 26 is transferred to the surface of the print medium 18 by the transfer roller 25. At that time, the transfer residual toner remaining on the surface of the photosensitive drum 26 is removed by the cleaning roller 29. The print medium 18 onto which the toner image has been transferred is further conveyed to the fixing mechanism unit 13.

  In the fixing mechanism section 13, the heat roller 16 is rotationally driven, and the backup roller 17 is driven to rotate as the heat roller 16 rotates. When the printing medium 18 is conveyed between the heat roller 16 and the backup roller 17, the printing medium 18 is heated and pressurized, and the toner image transferred by the printing mechanism unit 12 is fixed. Thereafter, the print medium 18 is conveyed from the fixing mechanism unit 13 to the paper discharge mechanism unit 14.

  As shown in FIG. 2, the paper discharge mechanism unit 14 includes discharge rollers 36 to 39 and a stacker 40 for accommodating the discharged print medium 18.

  When the printing medium 18 on which the toner image is fixed by the fixing mechanism unit 13 is conveyed to the paper discharge mechanism unit 14, the discharge rollers 36 to 39 start rotating under the control of the printer control unit. The print medium 18 is conveyed by discharge rollers 36 and 37 and then discharged onto a stacker 40 provided on the upper surface of the printer 10 by discharge rollers 38 and 39.

Next, a detailed configuration of the image forming unit 23 will be described.
FIG. 4 is a side sectional view showing the configuration of an image forming unit including the toner stirring device according to the present invention.

  The image forming unit 23 includes a toner stirring device that is a developer stirring device and a developing device having the toner stirring device. The image forming unit 23 serves as a storage tank in which the toner 42 is stored in the unit main body 41. A toner hopper 43 is provided.

  A toner cartridge 32 that replenishes toner 42 in a toner holding space 34 (FIG. 3) formed by the toner hopper 43 is mounted on the upper portion of the unit main body 41 of the image forming unit 23. Further, as described with reference to FIG. 3, the photosensitive drum 26, the developing roller 28, and the sponge roller 30 are disposed inside the unit main body 41, and the sponge roller 30 develops the toner 42 accommodated in the toner hopper 43. The developing roller 28 supplies the supplied toner to the photosensitive drum 26.

Inside the toner hopper 43, a stirring bar 44 as a stirring member is provided.
FIG. 5 is a schematic perspective view of the stirring bar.
The stirring bar 44 is made of iron in the present embodiment, and is rotatably supported by a bearing driving member and a bearing member described later. As shown in FIG. 5, the stirring bar 44 has a stirring portion 44c parallel to the rotation axis, and orthogonal portions 44b and 44b ′ extending in a direction orthogonal to both ends of the stirring portion 44c, and further, both end portions Are provided with shaft portions 44a and 44a 'serving as rotational axes that coincide with the rotational axis. The agitation bar 44 rotates about the shafts 44a and 44a 'in the direction indicated by the arrow A, and agitates the toner 42 accommodated in the toner hopper 43 by the agitation unit 44c.

In the image forming unit 23, a sensor unit 35 as a position detection unit is disposed below the bottom surface of the toner hopper 43.
FIG. 6 is an explanatory diagram showing the configuration and operation of the sensor unit.
6 (a) and 6 (b) are explanatory views showing the rotation operation of the sensor lever, and FIG. 6 (c) is a plan view of the sensor lever as viewed from above (on the toner hopper 43 side).

  The sensor unit 35 includes a sensor lever 46 as shown in FIGS. 6 (a) to 6 (c). As shown in FIGS. 6 (a) and 6 (b), the sensor lever 46 is formed in a substantially square shape, is provided with a magnet 47 at the tip, and is supported at a substantially central portion so as to be rotatable on a support shaft 48. Is done.

  A sensor 49 for detecting the rear end position of the sensor lever 46 is disposed in the vicinity of the rear end of the sensor lever 46. In this embodiment, the sensor 49 includes a photosensor having a light emitting element and a light receiving element, detects a light projecting state or a light shielding state, and outputs an on / off signal to the printer control unit according to the detection.

For example, in FIG. 6A, the stirring portion 44c of the stirring bar 44 is at the lowest position of the bearing drive member 45 with which the shaft portion 44a is engaged, that is, a position away from the bottom dead center position. At this time, the front end of the sensor lever 46 is in a position lowered by its own weight, and the sensor 49 detects a light shielding state based on the position of the rear end of the sensor lever 46 and outputs an off signal.
On the other hand, FIG. 6B shows a case where the stirring portion 44c of the stirring bar 44 is at the bottom dead center position. At this time, the tip of the sensor lever 46 is lifted by rotating the magnet 47 counterclockwise from the state shown in FIG. The rear end is descending. Along with this, the sensor 49 detects the light projection state and outputs an ON signal.

  When the on / off signal is input from the sensor 49 as a position detection unit and a determination unit, the printer control unit determines the remaining amount of toner 42 in the toner hopper 43 based on the signal. That is, the printer control unit determines that the remaining amount of toner is not small when an off signal is input, and determines that the remaining amount of toner is small when an on signal is input.

  Note that a magnetic sensor may be applied as the position detection unit instead of the sensor unit 35. In this case, for example, by incorporating a magnet in the stirring unit 44c of the stirring bar 44, the magnetic sensor detects the strength of the magnetic field generated from the magnet. Then, the printer control unit can acquire the position information of the stirring unit 44c based on the detection information. The printer control unit determines the remaining amount of toner based on the acquired position information.

Next, the configuration of the toner stirring device of this embodiment will be described.
FIG. 1 is a cross-sectional view illustrating a main configuration of a toner stirring device according to a first embodiment of the present invention.
FIG. 1A is a diagram illustrating a case where the stirring unit 44c of the stirring bar 44 is at the top dead center position in the toner stirring device 50, and FIG. 1B is a diagram illustrating the case where the stirring unit 44c is at the bottom dead center position. It is a figure which shows a case.

  In the toner stirring device 50 of the present embodiment, a bearing member 51 and a bearing drive member 45 that rotatably support the stirring bar 44 are provided on the side wall portion of the toner hopper 43, respectively.

  The bearing member 51 is fixed to the side wall portion of the toner hopper 43 and engages with one shaft portion 44a ′ of the stirring bar 44 as shown in FIGS. 1 (a) and 1 (b).

FIG. 7 is a perspective view showing the configuration of the bearing member.
As shown in FIG. 7, the bearing member 51 has an open end. As shown in FIG. 1A and FIG. 1B, the shaft portion 44a ′ of the stirring bar 44 is inserted into the open end portion. The inner diameter of the open end of the bearing member 51 can move the stirring bar 44 in the rotation axis direction, that is, the direction indicated by the arrow B (FIG. 1A) or the direction indicated by the arrow C (FIG. 1B). Therefore, it is larger than the outer diameter of the shaft portion 44a ′. Further, as shown in FIG. 7, the open end portion is provided with an inclined portion 51a as a bearing inclined portion. The bearing member 51 rotates the stirring bar 44 based on the shape of the inclined portion 51a. Regulate the axial position.

  The bearing driving member 45 is disposed on the side wall portion of the toner hopper 43 as a bearing member and a driving portion, and is engaged with one shaft portion 44a of the stirring bar 44 as shown in FIGS. 1 (a) and 1 (b). Match.

FIG. 8 is a perspective view illustrating a configuration of a bearing drive member in the first embodiment.
As shown in FIG. 8, the bearing driving member 45 includes a cylindrical portion 52 and a stirring gear 53 connected to the cylindrical portion 52.

  As shown in FIGS. 1A and 1B, the cylindrical portion 52 of the bearing driving member 45 is rotatably supported on the side wall portion of the toner hopper 43, and the shaft portion 44a of the stirring bar 44 is provided therein. Plugged in. The inner diameter of the cylindrical portion 52 is larger than the outer diameter of the shaft portion 44a, similarly to the inner diameter of the open end portion of the bearing member 51.

  As shown in FIG. 8, the cylindrical portion 52 is formed with a notched portion at the open end, and has a drive portion 52a, an inclined portion 52b, and an abutting portion 52c in the notched portion.

The drive part 52 a is a part that presses the shaft part 44 a of the stirring bar 44 and rotationally drives the stirring bar 44.
The inclined portion 52b, as a bearing inclined portion, regulates the position of the stirring bar 44 in the rotation axis direction based on its shape.
The abutting portion 52c is a portion that abuts on the stirring bar 44 when dropped to the bottom dead center position of the stirring bar 44 (FIG. 1B).

  Further, the bearing driving member 45 has one end portion of the cylindrical portion 52 protruding outside the side wall portion of the toner hopper 43. And the stirring gear 53 is connected with this protrusion part. The agitation gear 53 rotates with the rotation of the photosensitive drum 26 (FIG. 4), and drives the cylindrical portion 52 to rotate. The state of this rotation will be described with reference to FIG.

FIG. 9 is a side sectional view (No. 2) showing the configuration of the image forming unit including the toner stirring device according to the present invention.
As shown in FIG. 9, a gear member 54 that meshes with the photosensitive drum 26, a gear member 55 that meshes with the gear member 54, and a gear member 56 that meshes with the gear member 55 rotate inside the image forming unit 23. A drive mechanism is provided for each.

  When the photosensitive drum 26 rotates in the direction indicated by the arrow in FIG. 9 by the driving force of the motor (not shown), the gear members 54, 55 and 56 rotate in the arrow direction shown in FIG. Then, the stirring gear 53 that meshes with the gear member 56 rotates in the direction indicated by the arrow A.

  Along with the rotation of the rotation drive mechanism portion, both the stirring gear 53 and the cylindrical portion 52 of the bearing drive member 45 rotate. At this time, when the drive part 52a of the cylindrical part 52 comes into contact with the shaft part 44a of the stirring bar 44, the stirring bar 44 is pressed with the shaft part 44a by the drive part 52a and rotates together with the bearing drive member 45. Become.

Next, the rotation operation of the stirring bar 44 in the toner stirring device 50 of this embodiment will be described in detail.
First, in the case where a large amount of toner 42 is accommodated in the toner hopper 43, the stirring operation of the toner 42 in the toner stirring device 50 and the remaining amount determination operation of the toner 42 in the printer 10 in which the toner stirring device 50 is mounted. Will be described with reference to the drawings.
FIG. 10 is an explanatory diagram (part 1) illustrating the stirring operation in the first embodiment of the toner stirring device according to the present invention.

  In the toner agitating device 50, the bearing drive member 45 (FIG. 1) is rotated at a constant speed in synchronization with the rotation of the photosensitive drum 26 by the rotation drive mechanism shown in FIG. When the driving portion 52a of the cylindrical portion 52 comes into contact with the shaft portion 44a of the stirring bar 44, the shaft portion 44a is pressed against the driving portion 52a as the bearing driving member 45 rotates. As a result, the stirring bar 44 is driven to rotate and rotates in the direction of arrow A as shown in FIGS. 10 (a) and 10 (b).

  The bearing drive member 45 and the stirring bar 44 rotate together, and the stirring portion 44c of the stirring bar 44 reaches the top dead center position as shown in FIGS. When the dead center position is slightly passed, the stirring bar 44 rotates faster than the driving unit 52a due to its own weight and falls. Then, the stirring bar 44 stops when the stirring unit 44c reaches the upper surface of the toner 42 deposited on the toner hopper 43, as shown in FIG. In other words, the remaining amount of toner 42 in the toner hopper 43 can be determined based on the stop position of the stirring unit 44c.

  In the printer 10 equipped with the toner agitation device 50, the printer control unit is based on an input signal from the sensor unit 35 immediately after the driving unit 52a of the bearing driving member 45 reaches the uppermost position (FIG. 10C). The remaining amount of toner 42 is determined. As shown in FIG. 10 (d), when the stirring unit 44c stops at a position away from the bottom dead center position, the tip of the sensor lever 46 of the sensor unit 35, as shown in FIG. 6 (a), It is descending due to its own weight. At this time, the sensor 49 detects a light shielding state based on the rear end position of the sensor lever 46 and outputs an off signal. Based on the input of the off signal from the sensor 49, the printer control unit determines that the stop position of the stirring unit 44c is not the bottom dead center position, that is, the remaining amount of the toner 42 in the toner hopper 43 is not small.

  The bearing driving member 45 continues to rotate at a constant speed even after the stirring bar 44 is dropped. When the drive unit 52a catches up with the stirring bar 44 and contacts the shaft portion 44a, the drive portion 52a rotates while pressing the shaft portion 44a. As a result, the stirring portion 44c of the stirring bar 44 is pushed into the toner 42 deposited on the toner hopper 43, and rotates while stirring the toner 42 (FIG. 10E). Then, the toner agitation device 50 repeats the operations shown in FIGS. 10A to 10E.

  As described above, the remaining amount of the toner 42 in the toner hopper 43 is determined based on the signal from the sensor unit 35.

Next, the stirring operation of the toner stirring device 50 and the toner remaining amount determination operation of the printer 10 when the remaining amount of toner 42 in the toner hopper 43 is small will be described.
FIG. 11 is an explanatory diagram (part 2) illustrating the stirring operation in the first embodiment of the toner stirring apparatus according to the present invention.

  When the drive part 52a of the bearing drive member 45 contacts the shaft part 44a of the stirring bar 44 (FIG. 11A), the drive part 52a rotates while pressing the shaft part 44a, and the stirring bar 44 11 (a) and 11 (b), the bearing drive member 45 rotates in the direction indicated by the arrow A.

  When the stirring portion 44c of the stirring bar 44 reaches the top dead center position as shown in FIGS. 1 (a) and 11 (c), the stirring bar 44c passes the top dead center position slightly. 44 rotates faster than the drive part 52a by its own weight, and falls. At this time, since only a small amount of toner 42 is accommodated in the toner hopper 43, the stirring bar 44 drops to the bottom dead center position as shown in FIG. 11D, and FIG. ), The shaft portion 44a collides with the contact portion 52c of the bearing drive member 45 and stops. At that time, the toner 42 (FIG. 11C) that has been hardened and unevenly distributed in the toner hopper 43 is stirred and spread by the stirring unit 44c (FIG. 11D).

  In the printer 10, the printer control unit controls the toner 42 in the toner hopper 43 based on the input signal from the sensor unit 35 immediately after the driving unit 52 a of the bearing driving member 45 reaches the uppermost position (FIG. 11C). Determine the remaining amount. At the time of stopping at the bottom dead center position of the stirring portion 44c, the tip of the sensor lever 46 of the sensor portion 35 rises as the magnet 47 is attracted to the iron stirring bar 44 as shown in FIG. 6 (b). The rear end of the sensor lever 46 is lowered. Therefore, the sensor 49 detects the light projection state and outputs an ON signal. Based on the input of the ON signal, the printer control unit determines that the stop position of the stirring unit 44c is the bottom dead center position, that is, the remaining amount of the toner 42 in the toner hopper 43 is small.

  The bearing drive member 45 continues to rotate at a constant speed, and when the drive part 52a contacts the shaft part 44a of the stirring bar 44, it rotates with the stirring bar 44 while pressing the shaft part 44a (FIG. 11 (e)). )). The toner stirring device 50 repeats the operations shown in FIGS. 11A to 11E.

  As described above, the stirring bar 44 falls to the bottom dead center position, and it is determined that the remaining amount of the toner 42 is small.

  By the way, in the conventional toner agitating device, when the amount of toner remaining in the toner hopper is small, the agitation bar rebounds or vibrates when dropped to the bottom dead center position (FIG. 16B). Therefore, there has been a problem that erroneous detection due to chattering phenomenon occurs, and accurate determination of the remaining amount of toner becomes impossible.

  On the other hand, in the toner agitating device 50 of the present embodiment, the agitation bar 44 is supported by the bearing drive member 45 and the bearing member 51 so as to be movable in the rotation axis direction, and during the fall to the bottom dead center position due to its own weight, If the orthogonal part 44b contacts the inclined part 52b of the bearing drive member 45, it falls smoothly along the inclined part 52b while maintaining the corresponding contact state. At this time, the stirring bar 44 moves in the direction indicated by the arrow C in FIG. 1B, that is, in the direction of the rotation axis, based on the shape of the inclined portion 52b. By smoothly falling in this manner, even when the shaft portion 44a of the stirring bar 44 collides with the contact portion 52c of the bearing drive member 45, the occurrence of chattering phenomenon is prevented since the occurrence of bounce and vibration is suppressed. Is done. Therefore, the printer 10 can accurately determine the remaining amount of toner 42 in the toner hopper 43.

  When the drive unit 52a catches up with the stopped stirring bar 44 and comes into contact with the shaft portion 44a (FIG. 11E), the stirring bar 44 is rotationally driven by the drive unit 52a to the top dead center position. It rises (FIGS. 11A to 11C). When the orthogonal portion 44b ′ contacts the inclined portion 51a of the bearing member 51 during the ascending, the stirring bar 44 maintains the corresponding contact state, based on the shape of the inclined portion 51a, as shown in FIG. It rises while moving in the direction indicated by arrow B, that is, in the direction of the rotation axis.

  As described above, the toner stirring device and the printer of this embodiment are provided with the inclined portions in the bearing member and the bearing driving member, and the stirring bar can be rotated and moved in the rotation axis direction by the bearing member and the bearing driving member. It is possible to suppress the occurrence of rebound and vibration when the stirring bar is dropped. Therefore, the remaining amount of toner can be accurately determined.

FIG. 12 is a cross-sectional view illustrating the main configuration of the toner stirring device according to the second embodiment of the present invention.
12A is a diagram showing a case where the stirring unit 44c of the stirring bar 44 is at the top dead center position in the toner stirring device 60, and FIG. 12B is a diagram where the stirring unit 44c is at the bottom dead center position. It is a figure which shows a case.
The toner stirring device 60 of the present embodiment is different from the first embodiment in that the inclined portion 61 a is provided on the side wall portion of the toner hopper 61.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In the toner stirring device 60 of the present embodiment, a bearing member 62 and a bearing driving member 45 that rotatably support the stirring bar 44 are provided on the side wall portion of the toner hopper 61, respectively.

  The bearing member 62 is fixed to the side wall portion of the toner hopper 61, and as shown in FIGS. 12A and 12B, one shaft portion 44a ′ of the stirring bar 44 is inserted into the open end portion thereof. Yes. The inner diameter of the open end portion of the bearing member 62 is larger than the outer diameter of the shaft portion 44a ′ so that the stirring bar 44 can be moved in the direction of the rotation axis.

  In the side wall portion of the toner hopper 61, an inclined portion 61a as a side wall inclined portion is formed at the upper portion of the fixing position of the bearing member 62 as shown in FIGS. 12 (a) and 12 (b). Based on the shape of the inclined portion 61a, the stirring bar 44 is restricted in position in the rotation axis direction.

The agitating operation in the toner agitating device 60 of the present embodiment is substantially the same as that of the first embodiment.
When the remaining amount of toner in the toner hopper 61 is small, the stirring bar 44 is rotationally driven to the top dead center position by the bearing drive member 45 and then falls to the bottom dead center position by its own weight. At that time, when the orthogonal portion 44b comes into contact with the bearing drive member 45, the stirring bar 44 smoothly moves along the inclined portion 61a while moving in the direction indicated by the arrow C in FIG. 44a collides with the contact part 52c of the bearing drive member 45 and stops. At this time, since the rebound and vibration of the stirring bar 44 are suppressed, the remaining amount of toner is accurately determined.

  When the bearing drive member 45 is rotationally driven to the top dead center position, when the orthogonal portion 44b ′ contacts the inclined portion 61a of the toner hopper 61, the stirring bar 44 maintains the corresponding contact state and maintains the corresponding contact state. Ascending while moving in the direction indicated by arrow D in FIG.

  As described above, the toner stirring device of the present embodiment is the same as that of Embodiment 1 except that the toner hopper is provided with an inclined portion instead of the inclined portion provided on the bearing member. An effect can be obtained. Therefore, the occurrence of the chattering phenomenon is suppressed, and the toner remaining amount can be accurately determined.

FIG. 13 is a diagram illustrating a configuration of a bearing drive member in the third embodiment.
In the toner stirring device of the present embodiment, the shape of the inclined portion 72b provided in the cylindrical portion 72 of the bearing driving member 71 is different from that of the first embodiment.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In the toner stirring device of the present embodiment, the bearing driving member 71 includes a cylindrical portion 72 and a stirring gear 53 connected to the cylindrical portion 72 as a bearing member and a driving portion.

  As shown in FIG. 13, the cylindrical portion 72 of the bearing drive member 71 is formed with a notched portion at the open end, and has a drive portion 72 a, an inclined portion 72 b, and a contact portion 72 c.

  In the bearing drive member 45 of the first embodiment, the inclined portion 52b is formed by notching the cylindrical portion 52 with a straight line, as shown in FIG. On the other hand, in the bearing drive member 71 of this embodiment, as shown in FIG. 13, the cylindrical portion 72 is cut out by an arc to form an inclined portion 72b.

The stirring operation in the toner stirring apparatus of the present embodiment is almost the same as that of the first embodiment.
When the remaining amount of toner 42 in the toner hopper 43 is small, the stirring bar 44 is rotationally driven to the top dead center position by the bearing driving member 71 and then falls to the bottom dead center position by its own weight. At that time, the stirring bar 44 falls smoothly while moving in the direction of the rotation axis while the orthogonal portion 44b is in contact with the bearing drive member 71, and the shaft portion 44a collides with the contact portion 72c of the bearing drive member 45. Then stop. At the time of dropping, the stirring bar 44 can be more smoothly dropped based on the shape of the inclined portion 72b, so that the stirring bar 44 can be rebounded and vibrations can be further suppressed.

  As described above, the toner stirring device of the present embodiment can further suppress the occurrence of chattering by forming the inclined portion of the bearing driving member in an arc shape. Therefore, the remaining amount of toner can be determined more accurately.

FIG. 14 is a cross-sectional view illustrating the main configuration of the toner stirring apparatus according to the fourth embodiment of the present invention.
The toner stirring device 80 according to the present embodiment is different from the first embodiment in that the spring 82 for applying an elastic force to the bearing member 81 is provided.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In the toner stirring device 80 of the present embodiment, a bearing member 81 and a bearing driving member 45 that rotatably support the stirring bar 44 are provided on the side wall portion of the toner hopper 83, respectively.

  The bearing member 81 is disposed on the side wall portion of the toner hopper 83, and rotatably supports the shaft portion 44a 'of the stirring bar 44.

  In the bearing member 81, on the back side of the support surface that supports the stirring bar 44, as shown in FIG. One end of the spring 82 is fixed to the bearing member 81 and the other end is fixed to the inner surface of the toner hopper 83 in a state of being contracted from the natural length. The spring 82 always applies an elastic force in the direction indicated by the arrow F in FIG. 14, that is, the rotational axis direction, to the bearing member 81 and the stirring bar 44 supported by the bearing member 81.

The stirring operation in the toner stirring device 80 of this embodiment is substantially the same as that of the first embodiment.
The agitation bar 44 rotates while its position in the rotation axis direction is regulated by the spring 82 based on the elastic force in the rotation axis direction applied via the bearing member 81 and the shape of the bearing drive member 45. Since the stirring bar 44 falls by its own weight smoothly along the inclined portion 52b of the bearing drive member 45, the occurrence of rebound and vibration at the time of collision with the contact portion 52c is prevented.

  As described above, the toner agitating device of the present embodiment arranges the bearing member so as to be movable in the rotation axis direction, and provides a spring for applying an elastic force to the agitation bar via the bearing member. Occurrence can be prevented. Therefore, it is possible to accurately determine the remaining amount of toner.

FIG. 15 is a diagram illustrating a configuration of a bearing drive member in the fifth embodiment.
The toner stirring device of the present embodiment is substantially the same as the configuration of the toner stirring device 80 of the fourth embodiment, and the shape of the inclined portion 92b provided in the cylindrical portion 92 of the bearing driving member 91 is different from that of the fourth embodiment. Different.
In the present embodiment, the same components as those in the fourth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In the toner stirring device of the present embodiment, the bearing driving member 91 includes a cylindrical portion 92 and a stirring gear 53 connected to the cylindrical portion 92 as a bearing member and a driving portion.

  As shown in FIG. 15, the cylindrical portion 92 of the bearing drive member 91 has a drive portion 92a, an inclined portion 92b, and a contact portion 92c.

  In the bearing drive member 45 of the first and fourth embodiments, the inclined portion 52b is formed by cutting out the cylindrical portion 52 from the substantially central portion toward the open end as shown in FIG. . On the other hand, in the bearing drive member 91 of the present embodiment, as shown in FIG. 15, the inclined portion 92 b is formed by cutting the cylindrical portion 92 from the substantially central portion toward the connecting portion with the stirring gear 53. .

The stirring operation in the toner stirring apparatus of the present embodiment is almost the same as that of the fourth embodiment.
The stirring bar 44 rotates while its position in the rotation axis direction is regulated, and after passing through the top dead center position, the stirring bar 44 smoothly falls by its own weight along the inclined portion 92b of the bearing drive member 91. The occurrence of rebound and vibration at the time of collision is suppressed.

  As described above, the toner stirring apparatus of the present embodiment can obtain the same effect as that of the fourth embodiment by applying an elastic force to the stirring bar and changing the shape of the inclined portion of the bearing driving member. . Therefore, it is possible to accurately determine the remaining amount of toner.

  In each embodiment of the present invention, the fact that the bearing drive member as the bearing member includes an inclined portion as a bearing inclined portion having an inclination with respect to the direction of the rotating shaft in the contact portion with the stirring bar as the stirring member is only The stirring bar is only an example for implementing the idea that the stirring bar is rotated along the rotating direction of the rotating shaft and moved along the axial direction of the rotating shaft, and the present invention is not necessarily limited to this. Needless to say.

  In each embodiment of the present invention, a printer is described as an example of the image forming apparatus on which the developer stirring device and the developing device are mounted. However, the present invention is not limited to this. The present invention can be applied to image forming apparatuses such as scanners, facsimile machines, copiers, and multifunction machines.

1 is a cross-sectional view illustrating a configuration of a main part of a toner stirring device according to Embodiment 1 of the present invention. 1 is a schematic sectional side view showing a configuration of a printer according to the present invention. It is a schematic sectional side view which shows the structure of a printing mechanism part. FIG. 3 is a side sectional view (No. 1) showing a configuration of an image forming unit including a toner stirring device according to the present invention. It is a schematic perspective view of a stirring bar. It is explanatory drawing which shows the structure and operation | movement of a sensor part. It is a perspective view which shows the structure of a bearing member. It is a perspective view which shows the structure of the bearing drive member in Example 1. FIG. FIG. 6 is a side cross-sectional view (part 2) illustrating the configuration of the image forming unit including the toner stirring device according to the present invention. FIG. 3 is an explanatory diagram (part 1) illustrating a stirring operation in the first embodiment of the toner stirring device according to the present invention. FIG. 6 is an explanatory diagram (part 2) illustrating the stirring operation in the first embodiment of the toner stirring device according to the present invention. It is sectional drawing which shows the principal part structure of the toner stirring apparatus which concerns on Example 2 of this invention. It is a figure which shows the structure of the bearing drive member in Example 3. FIG. FIG. 6 is a cross-sectional view illustrating a main configuration of a toner stirring device according to a fourth embodiment of the present invention. It is a figure which shows the structure of the bearing drive member in Example 5. FIG. It is explanatory drawing which shows the conventional toner stirring apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Printer 23 Image forming unit 35 Sensor part 42 Toner 43 Toner hopper 44 Stirring bar 44a, 44a 'Shaft part 44b, 44b' Orthogonal part 44c Stirring part 45 Bearing drive member 50 Toner stirrer 51 Bearing member 51a Inclination part 52a Drive part 52b Inclination Part 52c contact part 53 stirring gear

Claims (10)

A storage tank for storing the developer;
An agitation member having at least one shaft portion, for agitating the developer accommodated in the accommodating tank;
A bearing member that engages with the shaft portion and supports the stirring member so as to be rotatable around the rotation shaft and movable in the axial direction of the rotation shaft, with the shaft portion serving as a rotation shaft;
A drive unit for rotationally driving the stirring member;
A determination unit for determining a remaining amount of the developer in the storage tank;
A developer stirring device comprising:
The developer stirring device, wherein the stirring member is rotated along a rotation direction of the rotation shaft and is moved along an axial direction of the rotation shaft.   The said determination part has a position detection part which detects the position of the said stirring member at predetermined | prescribed timing, The determination of the said residual amount is performed based on the detected said position. Developer stirring device.   The developer agitating device according to claim 1, wherein the driving portion is provided at an end portion of the bearing member and drives the shaft portion by pressing the shaft portion.   The developer agitating device according to claim 1, further comprising an imparting portion that imparts an elastic force in the axial direction to the agitating member. The developer stirring device according to claim 1, wherein the bearing member includes a bearing inclined portion having an inclination with respect to the axial direction at a contact portion with the stirring member.   The developer agitating device according to claim 5, wherein the bearing inclined portion has an arc-shaped inclination. The developer agitator according to claim 1, wherein the storage tank has a restricting portion for restricting movement of the agitating member in the axial direction.   The developer agitating device according to claim 7, wherein the restriction portion includes a side wall inclined portion formed on a side wall portion of the storage tank.   A developing device comprising the developer stirring device according to claim 1.   An image forming apparatus comprising the developing device according to claim 9.

Images